A farmer herds ducks at a rice field in Ayutthaya province, 80 km ( 50 miles) north of Bangkok,January 24, 2008. The H5N1 bird flu virus has re-emerged in a northern Thai province for the first time since March last year, forcing the slaughter of 10,000 chickens, an Agriculture Ministry official said on Thursday. REUTERS/Sukree Sukplang (THAILAND)